kernel/linux.git/fs/exfat, branch v6.1.168

exfat: fix remount failure in different process environments

2026-01-11T14:18:48+00:00

[ Upstream commit 51fc7b4ce10ccab8ea5e4876bcdc42cf5202a0ef ] The kernel test robot reported that the exFAT remount operation failed. The reason for the failure was that the process's umask is different between mount and remount, causing fs_fmask and fs_dmask are changed. Potentially, both gid and uid may also be changed. Therefore, when initializing fs_context for remount, inherit these mount options from the options used during mount. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202511251637.81670f5c-lkp@intel.com Signed-off-by: Yuezhang Mo Signed-off-by: Namjae Jeon Signed-off-by: Sasha Levin

exfat: check return value of sb_min_blocksize in exfat_read_boot_sector

2025-12-06T21:12:37+00:00

commit f2c1f631630e01821fe4c3fdf6077bc7a8284f82 upstream. sb_min_blocksize() may return 0. Check its return value to avoid accessing the filesystem super block when sb->s_blocksize is 0. Cc: stable@vger.kernel.org # v6.15 Fixes: 719c1e1829166d ("exfat: add super block operations") Reviewed-by: Christoph Hellwig Signed-off-by: Yongpeng Yang Link: https://patch.msgid.link/20251104125009.2111925-3-yangyongpeng.storage@gmail.com Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

exfat: limit log print for IO error

2025-12-06T21:12:26+00:00

[ Upstream commit 6dfba108387bf4e71411b3da90b2d5cce48ba054 ] For exFAT filesystems with 4MB read_ahead_size, removing the storage device when the read operation is in progress, which cause the last read syscall spent 150s [1]. The main reason is that exFAT generates excessive log messages [2]. After applying this patch, approximately 300,000 lines of log messages were suppressed, and the delay of the last read() syscall was reduced to about 4 seconds. [1]: write(5, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 131072) = 131072 <0.000120> read(4, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 131072) = 131072 <0.000032> write(5, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 131072) = 131072 <0.000119> read(4, 0x7fccf28ae000, 131072) = -1 EIO (Input/output error) <150.186215> [2]: [ 333.696603] exFAT-fs (vdb): error, failed to access to FAT (entry 0x0000d780, err:-5) [ 333.697378] exFAT-fs (vdb): error, failed to access to FAT (entry 0x0000d780, err:-5) [ 333.698156] exFAT-fs (vdb): error, failed to access to FAT (entry 0x0000d780, err:-5) Signed-off-by: Chi Zhiling Signed-off-by: Namjae Jeon Signed-off-by: Sasha Levin

exfat: fix the infinite loop in exfat_find_last_cluster()

2025-04-10T12:33:37+00:00

[ Upstream commit b0522303f67255926b946aa66885a0104d1b2980 ] In exfat_find_last_cluster(), the cluster chain is traversed until the EOF cluster. If the cluster chain includes a loop due to file system corruption, the EOF cluster cannot be traversed, resulting in an infinite loop. If the number of clusters indicated by the file size is inconsistent with the cluster chain length, exfat_find_last_cluster() will return an error, so if this inconsistency is found, the traversal can be aborted without traversing to the EOF cluster. Reported-by: syzbot+f7d147e6db52b1e09dba@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f7d147e6db52b1e09dba Tested-by: syzbot+f7d147e6db52b1e09dba@syzkaller.appspotmail.com Fixes: 31023864e67a ("exfat: add fat entry operations") Signed-off-by: Yuezhang Mo Signed-off-by: Namjae Jeon Signed-off-by: Sasha Levin

exfat: fix soft lockup in exfat_clear_bitmap

2025-03-13T11:53:18+00:00

[ Upstream commit 9da33619e0ca53627641bc97d1b93ec741299111 ] bitmap clear loop will take long time in __exfat_free_cluster() if data size of file/dir enty is invalid. If cluster bit in bitmap is already clear, stop clearing bitmap go to out of loop. Fixes: 31023864e67a ("exfat: add fat entry operations") Reported-by: Kun Hu , Jiaji Qin Reviewed-by: Sungjong Seo Signed-off-by: Namjae Jeon Signed-off-by: Sasha Levin

exfat: fix the infinite loop in __exfat_free_cluster()

2025-01-17T12:34:37+00:00

[ Upstream commit a5324b3a488d883aa2d42f72260054e87d0940a0 ] In __exfat_free_cluster(), the cluster chain is traversed until the EOF cluster. If the cluster chain includes a loop due to file system corruption, the EOF cluster cannot be traversed, resulting in an infinite loop. This commit uses the total number of clusters to prevent this infinite loop. Reported-by: syzbot+1de5a37cb85a2d536330@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=1de5a37cb85a2d536330 Tested-by: syzbot+1de5a37cb85a2d536330@syzkaller.appspotmail.com Fixes: 31023864e67a ("exfat: add fat entry operations") Signed-off-by: Yuezhang Mo Reviewed-by: Sungjong Seo Signed-off-by: Namjae Jeon Signed-off-by: Sasha Levin

exfat: fix the infinite loop in exfat_readdir()

2025-01-17T12:34:37+00:00

[ Upstream commit fee873761bd978d077d8c55334b4966ac4cb7b59 ] If the file system is corrupted so that a cluster is linked to itself in the cluster chain, and there is an unused directory entry in the cluster, 'dentry' will not be incremented, causing condition 'dentry < max_dentries' unable to prevent an infinite loop. This infinite loop causes s_lock not to be released, and other tasks will hang, such as exfat_sync_fs(). This commit stops traversing the cluster chain when there is unused directory entry in the cluster to avoid this infinite loop. Reported-by: syzbot+205c2644abdff9d3f9fc@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=205c2644abdff9d3f9fc Tested-by: syzbot+205c2644abdff9d3f9fc@syzkaller.appspotmail.com Fixes: ca06197382bd ("exfat: add directory operations") Signed-off-by: Yuezhang Mo Reviewed-by: Sungjong Seo Signed-off-by: Namjae Jeon Signed-off-by: Sasha Levin

exfat: fix potential deadlock on __exfat_get_dentry_set

2024-12-19T17:08:51+00:00

commit 89fc548767a2155231128cb98726d6d2ea1256c9 upstream. When accessing a file with more entries than ES_MAX_ENTRY_NUM, the bh-array is allocated in __exfat_get_entry_set. The problem is that the bh-array is allocated with GFP_KERNEL. It does not make sense. In the following cases, a deadlock for sbi->s_lock between the two processes may occur. CPU0 CPU1 ---- ---- kswapd balance_pgdat lock(fs_reclaim) exfat_iterate lock(&sbi->s_lock) exfat_readdir exfat_get_uniname_from_ext_entry exfat_get_dentry_set __exfat_get_dentry_set kmalloc_array ... lock(fs_reclaim) ... evict exfat_evict_inode lock(&sbi->s_lock) To fix this, let's allocate bh-array with GFP_NOFS. Fixes: a3ff29a95fde ("exfat: support dynamic allocate bh for exfat_entry_set_cache") Cc: stable@vger.kernel.org # v6.2+ Reported-by: syzbot+412a392a2cd4a65e71db@syzkaller.appspotmail.com Closes: https://lore.kernel.org/lkml/000000000000fef47e0618c0327f@google.com Signed-off-by: Sungjong Seo Signed-off-by: Namjae Jeon Signed-off-by: Harshit Mogalapalli Signed-off-by: Greg Kroah-Hartman

exfat: support dynamic allocate bh for exfat_entry_set_cache

2024-12-19T17:08:51+00:00

commit a3ff29a95fde16906304455aa8c0bd84eb770258 upstream. In special cases, a file or a directory may occupied more than 19 directory entries, pre-allocating 3 bh is not enough. Such as - Support vendor secondary directory entry in the future. - Since file directory entry is damaged, the SecondaryCount field is bigger than 18. So this commit supports dynamic allocation of bh. Signed-off-by: Yuezhang Mo Reviewed-by: Andy Wu Reviewed-by: Aoyama Wataru Reviewed-by: Sungjong Seo Signed-off-by: Namjae Jeon Signed-off-by: Harshit Mogalapalli Signed-off-by: Greg Kroah-Hartman

exfat: fix uninit-value in __exfat_get_dentry_set

2024-12-14T18:54:00+00:00

commit 02dffe9ab092fc4c8800aee68cb7eafd37a980c4 upstream. There is no check if stream size and start_clu are invalid. If start_clu is EOF cluster and stream size is 4096, It will cause uninit value access. because ei->hint_femp.eidx could be 128(if cluster size is 4K) and wrong hint will allocate next cluster. and this cluster will be same with the cluster that is allocated by exfat_extend_valid_size(). The previous patch will check invalid start_clu, but for clarity, initialize hint_femp.eidx to zero. Cc: stable@vger.kernel.org Reported-by: syzbot+01218003be74b5e1213a@syzkaller.appspotmail.com Tested-by: syzbot+01218003be74b5e1213a@syzkaller.appspotmail.com Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon Signed-off-by: Greg Kroah-Hartman